Apparatus for exploring atmospheres for respiration and explosion hazards



- Oct. 27, 1936. Q U N 2,058,896

APPARATUS FOR EXPLORING' ATMOSPHERES FOR RESPIRATION AND EXPLOSIONHAZARDS Filed Alig. 26, 1952 2.Sheets-Sheet 1 Z7 4 mil '9 l m iw 5 I Q LINVENTOR.

UMrZeazYZzUzw .0cx.;21, 1936. c. A. LUNN 2,058,896

APPARATUS FOR EXPLORING ATMOSPHERES FOR RESPIRATION AND EXPLOSIONHAZARDS Filed Aug. 26, 1932 2 Sheets-Sheet 2 IN VEN TOR.

BY M .--/ATTORNEY.

Patented Oct. 27, 1936 UNITED STATES APPARATUS FOR EXPLORING ATMOS-PHERES FOR RESPIRATION AND EXPLO- SION HAZARDS Charles A. Lunn, NewCaanan, Conn., assignor to Consolidated Edison Company of New York,

Inc., a corporation of New York Application August 26,

9 Claims.

This invention relates to apparatus for exploring atmospheres forrespiration and explosion hazards, and is an improvement upon theinvention disclosed in the Lunn, Tomkins and Nacovsky application Ser.No. 609,020 filed May 3,

The present improvements provide generally for greater facility andscope in the use of the apparatus disclosed in said application. 7

The present improvements provide for speeding the toxic gas indication,particularly in cold weather, thereby making the device more remje inthe hands of the ordinary user. They provide improved means forindicating the n. ation of combustible gas or vapor when .sent above thelower explosive limit, and/or when the atmosphere contains insufficientoxygen to support complete combustion'of the combustible. Other featuresof improvement will be found set forth in the description which follows.

An embodiment of my present invention is illustrated in the accompanyingdrawings, .wherein Fig. l is a top plan view of said embodiment whichincludes the present improvements.

Fig. 2 is a rear elevation.

Fig. 3 is an end elevation.

Fig. 4 is a perspective view of the jacket seen in Figs. 1, 2 and 3.

Fig. 5 is an enlarged detail view, partly in section, of the pipes,etc., seen in Fig. 3.

Only sufficient description of the complete apparatus to understand thepresent improvements will be herein given, reference being made to saidearlier application for a full description of said apparatus and itsoperation.

Referring to said drawings, numeral ll] designates a means forindicating the presence of a toxic gas, as carbon monoxide, I2 a meansfor indicating the presence of combustible gases or vapors and of theconcentration thereof particularly with relation to the lower explosivelimit thereof (inclusive of a toxic combustible gas if present), and M ameans for indicating the presence of combustible gases and vapors, andalso of deficiency in oxygen, the means l4 preferably comprising aburner for producing a flame. The means or element 14 may be used inconjunction with the element l2, for differentiating between adeficiency in oxygen, and the presence of combustible gases and vaporsin concentrations above the lower explosive limit; and for determiningwhether sumcient oxygen is present in the atmosphere under test toeffect 'com- 1932, Serial No. 630,507

plete combustion of its combustible gas or vapor content in element 12.

Numeral l6 designates a pump or aspirator which is preferably arrangedso as to supply samples of an atmosphere to be explored or tested to theelements l0, l2 and I4. A sample of the atmosphere tested is an amountof the atmos-' phere to be tested sufficient to fill the chambers of theseveral elements in combination. The sample fractions may be distributedto said elements in any suitable manner. One mode of distribution is tosupply the sample fractions to the elements serially, the elements beingconnected by serial ducts, as hereinafter more fully described.

The toxic gas indicator preferably comprises a closed chamber 20 havingmeans 2| for giving a chemical indication of the presence of toxic gasin the sample of atmosphere being explored. For testing for carbonmonoxide, the means 21 may be a piece of absorbent paper which has beendipped in a water solution of palladium chloride containing ananti-freeze, such as glycerine or ethylene glycol. The toxic gasindicator III for the elements It], I2 and 14 may comprise more than onechamber 20, or more than one means 2| in chamber 20, when, for example,it is desired to test for the presence of more than one toxic gas.

Samples of atmosphere may be admitted to chamber 20 of element ll]through a duct 21, a fraction of the sample remaining in the chamber 20.A cock 2!] is preferably connected with duct 21, and a sampling tube orhose may have one end connected to the nipple on duct 21, the free endof the hose being introduced into the space or various parts thereofcontaining the atmosphere to be explored. 33 designates a duct, leadingfrom chamber 20 to element 12, through which, in the illustratedembodiment the sample fractions for elements 12 and I4 pass, which duct33 is preferably controlled by a three-way cook 35.

The element I2 may be any electrical circuit suitable for measuring achange in the electrical resistance or electrical current in one of itsparts, as for example a Wheatstone bridge type of circuit containing aresistance R with which the sample fraction of atmosphere is broughtinto contact. The resistance R is preferably a hot wire the electricalcharacteristics of which are changed by a heat change, i. e. by either aloss or gain of heat. In the embodiment chosen for illustration theatmospherein which combustible gas or vapor is present burns around thewire,

the heat of combustion augmenting the heat of the wire, therebyincreasing the resistance of the wire, and thereby causing thegalvanometer pointer to move to an extent proportional to theconcentration of combustible gas in the sample fraction of atmosphere.

The Wheatstone bridge contains the four normally balanced resistances RR R R in the four legs of the circuit, current being supplied insuitable manner, as by a storage battery or by dry-cells S, the circuitbeing balanced by adjustment of rheostat T. G designates a galvanometerconnected in the bridge wire of the circuit. The resistances R may be aplatinum wire enclosed in a tube or chamber 36, into which a fraction orfractions of samples of atmosphere may be introduced by means of a tubeor duct 31 which may be connected to the outlet duct 33 from chamber 20as heretofore explained. The fraction or fractions of samples ofatmosphere may pass out of tube 36 through a duct 38, which ispreferably also connected to a nippled coupling on the receptacle 4|.

The electrical change produced by the burning of a combustible gasaround the hot wire in element I2 is indicated and measured by agalvanometer G.

The galvanometer G is preferably equipped with a scale calibrated withreference to the lower explosive limit of mixtures of combustible gasesand vapors with air which is undiluted except for the combustible gastherein. For example, the scale shown on G of element I2 may becalibrated in fractions of the lower explosive limit (the lowerexplosive limit being 10 on the scale illustrated) of mixtures ofcombustible gases and vapors with air. The position of 10 on the scaledesignates the least concentration of combustible gas or vapor in airwhich will explode if ignited.

The numbers below 10 indicate proportionally concentrations ofcombustible gas and/or vapor in terms of the quantity required to form alower explosive limit mixture with air.

In the illustrated embodiment, the fraction of sample of atmospherewhich is to be tested in element I4 is passed through element I2,passing from element I2 through the nipple 40, to the pump I6 from whichit is forced into element I4 through the nipple 55.

The element I4 is preferably an indicator of the flame-type, andcomprises a burner for producing a relatively steady flame, as a wickdipping into a combustible liquid contained in a font 41. The burner iscontained in a chamber 49 into which sufficient air is normally admittedto maintain a steady flame. The hot gases leave element I4 throughopenings 18 in a shield 19.

The chamber 49 is preferably made transparent by forming its sides ofglass-tubing 53.

The glass tube 53 may be provided with a datum line 8| or a hingedmirror 80 may be provided with 5. datum line etched or scratchedthereon, serving as a reference line for adjusting the height of theflame from burner 45 and for assistance in interpreting the effects ofthe fraction or fractions of samples of atmosphere on the flame.

The pump or aspirator I6 as heretofore stated may be located betweenelements I2 and I4, being connected to nipples 40 and 55 by means ofhose or tubing 85. The pump is conveniently a collapsible rubber bulbhaving an inwardly-opening valve on its intake side and anoutwardly-opening valve on its discharge side.

Means are provided for supplying heat to the chamber 20 of element I0 tohasten, particularly in cold weather, the chemical reaction therein bywhich the presence of toxic gas is indicated. This heating-meanspreferably comprises a jacket I00 surrounding jointly the shield I9 ofelement I4 and the chamber 20, and heating the chamber 20 by the hot gasfrom the flame of burner 45 which issues through the slots 18 in shield19. The jacket I00 may comprise two shells or halves IDI, I 02, hingedtogether, as indicated at I04, and held in closed position by a latchI06 or other suitable means. The shells IOI, I02 may have flanges I08formed on the upper parts thereof which rest upon the upper parts ofchamber 20 and shield 19. The heating means described makes use of theheat already available from the flame of burner 45 and minimizes thechance of a user making an incorrect report as to the presence of toxicgas.

The cock 35 of element I2 has a passage IIO leading directly to theatmosphere, which passage III] is closely controlled by a valve, as theneedle-valve H2 illustrated. The three-way cock 35 in conjunction withducts 33 and H0 may function, therefore, to admit to element I2 (1) afraction of the sample of atmosphere being explored, without airdilution; (2) a fraction of the sample diluted with air; and (3) airalone.

A pipe II5 (Figs. 3 and 5) is preferably provided which leads from duct21, at a point ahead of cock 29, (and hence ahead of chamber 20 ofelement I0) to duct 33 ahead of cock 35, (and hence beyond chamber 20and ahead of the chamber 36 of element I2), which may serve as a by-passaround element I 0 and a cock I20 is provided in duct 33 for placingelement i2 in communication with element I0, or around element I0through the by-pass provided by pipe IE5. The element I2, provided withmeans for admitting air simultaneously with air containing combustiblegas or vapor, such as tho threc-wa5- cock 35, described, is an improvedelement per se.

Normally needle-valve H2 is closed, cock 35 in the position to open duct33 and close duct H0, cock 29 open, and cock I 20 in position to closepipe H5 and open duct 33 through chamber 20 of element I0.

After a fraction sample of the atmosphere to be explored has beensupplied to the element I0, it may be trapped in chamber 20 by closingcook 29 and turning cock I20 to close duct 33 to chamber 20 and open itto pipe H5 (position shown in Fig. 5). This will permit tests of theatmosphere being explored to be continued in elements I2 and I4 on otherlike samples or samplefractions of the same atmosphere being exploredWhile time is provided for insuring completion of the reaction on thesample-fraction in element I0.

As pointed out in said earlier application a position of the pointer ofgalvanometer G at I0 on the scale (1 on the scale in said earlierapplication) indicates that the concentration of combustible gas orvapor in the atmosphere being explored, is at the lower explosive limit.

As was also pointed out in said application, the indication of thepointer of galvanometer G may be erroneous, because of insuflicientoxygen in the atmosphere being explored to effect complete combustion ofthe combustible gas present.

To ascertain the nature and degree of the explosive hazard, and thecompleteness of the indication of element I2, the three-way cock 35 andvalve II 2 are manipulated, and the pumping continued.

If the pointer of galvanometer G stands at or below H] on the scale andupon opening valve l I 2, with cock in the position shown in Fig. 5, andcontinuing the supply through duct 33 of samplefractions of the sameatmosphere being tested (thereby diluting the sample with air) thepointer swings from a position at or below It to a higher part of thescale, this indicates that the atmosphere being explored containsinsufficient oxygen to efiect complete combustion of the combustible gasin the atmosphere, that the original indication was erroneous, and thatthe combustible gas or vapor is present in a higher concentration thanshown by the original indication of concentration. By graduating theopening through passage Hi! and continuing the testing on othersample-fractions of the same atmosphere being tested, an indication ofthe true concentration of combustible gas in the atmosphere being testedcan be obtained.

If the flame of burner 35 in element l4 lengthens and extin-guishes,when a fraction sample of the atmosphere being. explored is pumped intochamber 59, this indicates that the atmosphere being tested contains gasor vapor in a concentration above the lower explosive limit.

If under a similar manipulation the flame of burner short-ens andextinguishes, this indicates a deficiency of oxygen in the atmospherebeing tested.

To be reliable and comprehensive the indications of element i2 must betaken with the indications of element [4.

The invention may receive other embodiments than that hereinspecifically illustrated and described.

What is claimed is:-

1. Apparatus for exploring atmospheres for respiration and explosionhazards comprising a chamber for containing means chemically reactive toa toxic gas; a chamber and a burner therein for producing a flame, saidchamber having a transparent portion through which said flame is visibleand a portion through which the heated gases escape, means for pumping afraction of a sample of atmosphere to be explored to each of saidchambers, and means for heating said firstnamed chamber by the heatedgases escaping from said chamber containing the burner.

2. Apparatus for exploring atmospheres for respiration and explosionhazards comprising a chamber for containing means chemically reactive toatoxic gas, a chamber and a burner therein for producing a flame, saidchamber having a transparent portion through which said flame is visibleand a portion through which the heated gases escape, means for pumping afraction of a sample of atmosphere to be explored to each of saidchambers, and a jacket around said first-named chamber and the portionof said other chamber through which the heated gases escape, saidfirst-named chamber being thereby heated by the heated gases from theflame in said other chamber.

3. Apparatus for exploring atmospheres for respiration and explosionhazards comprising a chamber for containing means chemically reactive toa toxic gas; a chamber and a burner therein for producing a flame, saidchamber having a transparent portion through which said flame is visibleand a portion through which the heated gases escape, means for pumping afraction of a sample of atmosphere to be explored to each of saidchambers, and a jacket around said firstnamed chamber and the portion ofsaid other chamber through which the heated gases escape,

said first-named chamber being thereby heated by the heated gases fromthe flame in said other chamber, said jacket comprising two hinged partsand means for retaining said hinged parts in closed position.

4. Apparatus for exploring atmospheres for respiration and explosionhazards, comprising a chamber and a wire therein the electricalconductivity of which is sensitive to temperature changes, means forpumping samples of an atmosphere to be explored to said chamber, meansfor producing combustion in said chamber of combustible gas in saidsample, and indicating means responsive to changes of electricalconductivity of said wire, said indicating means comprising a pointerresponsive to current-variations and a scale calibrated for positions ofsaid pointer corresponding to the efiect thereon of combustion in saidchamber of samples containing combustible gas in amounts at and belowthe lower explosive limit thereof in the presence of a normal supply ofoxygen, an air-duct communicating with said chamber, and a valve foropening and closing said air-duct, whereby observations may be made withand without the simultaneous ad mission of air to said chamber, tothereby check the accuracy of the position of said pointer on saidscale.

5. Apparatus for exploring atmospheres for respiration and explosionhazards, comprising a chamber and a wire therein the electricalconductivity of which is sensitive to temperature changes, means forpumping samples of an atmosphere to be explored to said chamber, meansfor producing combustion in said chamber of combustible gas in saidsample, and indicating means responsive to changes of electricalconductivity of said wire, said indicating means comprising a, pointerresponsive to current-variations and a. scale calibrated for positionsof said pointer corresponding to the effect thereon of combustion insaid chamber of samples containing combustible gas in amounts at andbelow the lower explosive limit thereof in the presence of a normalsupply of oxygen, an air-duct communicating with said chamber, and avalve for opening and closing said air-duct, whereby observations may bemade with and without the simultaneous admission of air to said chamber,to thereby check the accuracy of the position of said pointer on saidscale, and a second valve for regulating the opening in said air-duct.

6. Apparatus for exploring atmospheres for respiration and explosionhazards, comprising a chamber and a wire therein the electricalconductivity of which is sensitive to temperature changes, means forpumping samples of an atmosphere to be explored to said chamber, meansfor producing combustion in said chamber of combustible gas in saidsample, and indicating means responsive to changes of electricalconductivity of said wire, said indicating means comprising a pointerresponsive to current-variations and a scale calibrated for positions ofsaid pointer corresponding to the effect thereon of combustion in saidchamber of samples containing combustible gas in amounts at and belowthe lower explosive limit thereof in the presence of a normal supply ofoxygen, a duct leading to said chamber through which said samples ofatmosphere are introduced, an air-duct leading to said firstnamed duct,and a three-way valve arranged to open said first-named duct and closesaid airduct, or to open both said ducts, whereby observations may bemade with and without the simultaneous admission of air to said chamberto thereby check the accuracy of the position of said pointer on saidscale.

7. Apparatus for exploring atmospheres for respiration and explosionhazards, comprising a chamber and-a wire therein the electricalconductivity of which is sensitive to temperature changes, means forpumping samples of an atmosphere to be explored to said chamber, meansfor producing combustion in said chamber of combustible gas in saidsample, and indicating means responsive to changes of electricalconductivity of said wire, said indicating means comprising a pointerresponsive to current variations and a scale calibrated for positions ofsaid pointer corresponding to the effect thereon of combustion in saidchamber of samples containing combustible gas in amounts at and belowthe lower explosive limit thereof in the presence of a normal supply ofoxygen, a duct leading to said chamber through which said samples ofatmosphere are introduced, an air-duct leading to said first-named duct,and a three-way valve arranged to open said firstnamed duct and closesaid air-duct, or to open both said ducts, whereby observations may bemade with and without the simultaneous admission of air to said chamberto thereby check the accuracy of the position of said pointer on saidscale, and a second valve for regulating the opening in said air-duct.

8. Apparatus for exploring atmospheres for respiration and explosionhazards, comprising a chamber for containing means chemically reactiveto a toxic gas, means for heating said chamher; and a chamber and a wiretherein the electrical conductivity of which is sensitive to temperaturechanges; a duct connecting said firstnamed chamber serially with saidchamber containing said conducting wire, another duct from a point aheadof said first named chamber to a point beyond it and ahead of saidchamber containing said wire, passing around said firstnamed duct, andmeans controlling the passage through said duct so that fractions ofsamples of atmosphere may pass from said first-named chamber to saidchamber containing said wire, or to said chamber containing said wirethrough said duct which passes around said first-named chamber, and saidchamber containing said wire thereby receive fractions of samples ofatmosphere which have not been affected by the heat of said first-namedchamber and also successive fractions for successive tests therein, andmeans for pumping fractions of samples of an atmosphere to be exploredto each of said chambers.

9. Apparatus for exploring atmospheres for respiration and explosionhazards, comprising a chamber for containing means chemically reactiveto a toxic gas, a, chamber and a burner therein for producing a flame,said chamber having a transparent portion through which said flame isvisible and a portion through which the heated gases escape; and achamber and a wire therein the electrical conductivity of which issensitive to temperature changes, means for heating said first-namedchamber by the heated gases escaping from said chamber containing theburner: a duct connecting said first-named chamber serially with saidchamber containing said conducting wire, another duct passing aroundsaid firstnamed duct from a point ahead of said first named chamber to apoint beyond it and ahead of said chamber containing said wire, andmeans controlling the passage through said duct so that fractions ofsamples of atmosphere may pass from said first-named chamber to saidchamber containing said wire, or to said chamber containing said wirethrough said duct which passes around said first-named chamber, and saidchamber containing said wire thereby receives fractions of samples ofatmosphere which have not been affected by the heat of said first-namedchamber, and also successive fractions for successive tests therein; andmeans for pumping fractions of samples of an atmosphere to be exploredto each of said chambers.

CHARLES A. LUNN.

CERTIFICATE OF CORRECTION.

Patent n 2,058,896. I o October 27, 1936.

CHARLES A. LUNN.

It is hereby certified that error appears in the printed specificationor the above numbered patent requiring correction as follows: Page 1,second column, line 25, strike out the words "'for the elements 10, 12and 14" and insert the same after "atmosphere" in line 30; page 2, firstcolumn, line 45, before "sample" insert the; same page, second column,line 48, and page 3, first column, line 21-22, for "fraction sample"read sample fraction; page 4,

--first column, beginning with the word "from" in line 39, claim 8,strike out all to and including the word "duct" in line 43, same claim,and insert instead the words passing around said first-named duct from'apoint ahead of" said first named chamber to a point beyond it and aheadof said chamber containing said wire; and second column, line 36, claim9, for "receives" read receive; and that the said Letters Patent shouldbe read with these corrections therein that the same may conform to therecord of the case in the Patent Office.

- Signed and sealed this 19th day of January, A. D. 1937.

"" enry Van Arsdale Acting Commissioner of Patents.

